I have exactly the same problem.
BUT, this time, it never connects to 5G anymore. It does not use the booster anymore. It always worked. My booster is outdoor in front of an Antenna. My phone at exactly the same place is full signal.
I am always at 40 MB/s (or 320Mbps or more) when I use the booster. But for a couple of days now, it is not functioning properly.
I tried to reboot my internet-box + booster (first the internet-box and afterwards the booster, and the other way too), nothing.
I tried to reset to factory settings my booster. Nothing.



Can anyone help? Thank you!